Keywords

air pollutantslungsalveolocytes of I type

Abstract

Objective: to study in dynamics the ultrastructural alterations in alveolocytes of type I caused by air pollutants. Materials and methods: experiments were done on 72 white male rats of 180-220 grams of weight during 30, 60 and 90 days in 2 zones. Zone I – ecologically clean zone, zone II – distant part of the city with developed industry. The sampling of lung tissue for electronic-microscopic examination was carried out under ketamine anaesthesia following the common protocol. Results: there was established that in the conditions of industrial air pollution one can observe increase of quantity of micropinocytotic vesicles in the peripheral part of alveolocytes of I type already in 30 days after beginning of the experiment. As research period increases (60-90 days), in many alveolocytes of I type dystrophic destructive changes can be observed. Nuclei of such cells have round or oval form with clarified nucleoplasm. Perinuclear space is expanded. Mitochondria have matrix of weak electron-optical density and reduced cristas. The Golgi sacs and canaliculi as well as those of granular endoplasm grid are expanded. The quantity of ribosomes on membranes of the latter is decreased. In some cells we observed sailfin protrusions of plasma membrane towards air vesicle lumen. Also, we found the areas with local destruction of cell membrane of peripheral parts of alveolocytes of I type. Basal membranes are thickened with unclear contours. At the same time, we found alveolocytes of I type with characteristics of increased functional activity. Conclusions: continuous stay of experimental animals in the conditions of industrial air pollution is accompanied by expressed changes of ultrastructural organization of alveolocytes of I type. Degree of expressiveness and character of changes in alveolocytes of I type depends on duration of time from the moment of primary alteration of air pollutants.